Mass flowmeters, such as Coriolis- and Vortex-type flowmeters measure the mass flow rate of materials flowing through a conduit. Exemplary Coriolis and Vortex flowmeters include the I/A Series Coriolis and the 83 Series Vortex flowmeters available from The Foxboro Company of Foxboro, Mass. Coriolis flowmeters, for example, have one or more conduits of straight or curved configuration. Each conduit configuration has a set of natural vibration modes. Each conduit is driven to oscillate at resonance in one of these natural modes. Material flows into the flowmeter from a connected pipeline on the inlet side of the flowmeter, is directed through the conduit or conduits, and exits the flowmeter through the outlet side thereof. The material flowing through the pipeline may be gas, liquid, solid, and any combination of these three. The natural vibration modes of the vibrating, material filled system are defined in part by the combined mass of the conduits and the material flowing within the conduits.
When there is no flow through the flowmeter, all points along the conduit oscillate due to an applied driver force with identical phase or small initial fixed phase offset. As material begins to flow, Coriolis forces cause each point along the conduit to have a different phase. The phase on the inlet side of the conduit lags the driver, while the phase on the outlet side of the conduit leads the driver. Sensors on the conduit(s) produce sinusoidal signals representative of the motion of the conduit(s). Signals output from the sensors are processed to determine the phase difference between the sensors. The phase difference between two sensor signals is proportional to the mass flow rate of material through the conduit(s).
In order to determine the flowmeter model of the proper size and parameters for a pipeline, flow stream parameters for the pipeline must be known. Flow stream parameters include material flow rate, material density, material viscosity, material temperature, and material operating pressure. From these flow stream parameters, parameters for a flowmeter to insert into the pipeline can be determined. Flowmeter parameters include meter accuracy, pressure loss, and material velocity. The flowmeter parameters and flow stream parameters are used to determine the models of flowmeters that can be used to measure mass flow rate in the pipeline.
It is common to use software programs executed by a computer to determine the proper model. However, this generally requires that meter selection and sizing occur on premises where the computer executing the software resides. A drawback of these systems is that users may attempt to select and size a meter using outdated software and/or flowmeter data. Other proposed systems have attempted to address this shortcoming by enabling a user to log onto a computer to remotely access sizing software and order a desired flowmeter without the intervention of a human operator. However, these proposed systems tend to be relatively limited, relying on a user to supply a relatively large number of flow stream parameters in order to produce a flowmeter recommendation. These systems also tend to be limited to single flowmeter types, are not easily scalable to include additional flowmeter types, and generally do not attempt to determine the compatibility of particular process fluids with materials from which the flowmeters may be fabricated.